[PATCH 2/4] MFD: ti_tscadc: disable TSC config registers in adc mode

[Zubair Lutfullah]

From: "Patil, Rachna" <rachna@xxxxxx>

AFE Pen Ctrl and TouchScreen transistors enabling is not
required when only ADC mode is being used, so check for availability of
TSC driver before accessing control register.

Signed-off-by: Patil, Rachna <rachna@xxxxxx>
Acked-by: Vaibhav Hiremath <hvaibhav@xxxxxx>
Signed-off-by: Zubair Lutfullah <zubair.lutfullah@xxxxxxxxx>
---
 drivers/mfd/ti_am335x_tscadc.c |   18 +++++++++++-------
 1 file changed, 11 insertions(+), 7 deletions(-)

diff --git a/drivers/mfd/ti_am335x_tscadc.c b/drivers/mfd/ti_am335x_tscadc.c
index b003a16..d72001c 100644
--- a/drivers/mfd/ti_am335x_tscadc.c
+++ b/drivers/mfd/ti_am335x_tscadc.c
@@ -208,13 +208,14 @@ static	int ti_tscadc_probe(struct platform_device *pdev)
 
 	/* Set the control register bits */
 	ctrl = CNTRLREG_STEPCONFIGWRT |
-			CNTRLREG_TSCENB |
-			CNTRLREG_STEPID |
-			CNTRLREG_4WIRE;
+			CNTRLREG_STEPID;
+	if (tsc_wires > 0)
+		ctrl |= CNTRLREG_4WIRE | CNTRLREG_TSCENB;
 	tscadc_writel(tscadc, REG_CTRL, ctrl);
 
 	/* Set register bits for Idle Config Mode */
-	tscadc_idle_config(tscadc);
+	if (tsc_wires > 0)
+		tscadc_idle_config(tscadc);
 
 	/* Enable the TSC module enable bit */
 	ctrl = tscadc_readl(tscadc, REG_CTRL);
@@ -294,10 +295,13 @@ static int tscadc_resume(struct device *dev)
 	pm_runtime_get_sync(dev);
 
 	/* context restore */
-	ctrl = CNTRLREG_STEPCONFIGWRT | CNTRLREG_TSCENB |
-			CNTRLREG_STEPID | CNTRLREG_4WIRE;
+	ctrl = CNTRLREG_STEPCONFIGWRT |	CNTRLREG_STEPID;
+	if (tscadc_dev->tsc_cell != -1)
+		ctrl |= CNTRLREG_TSCENB | CNTRLREG_4WIRE;
 	tscadc_writel(tscadc_dev, REG_CTRL, ctrl);
-	tscadc_idle_config(tscadc_dev);
+
+	if (tscadc_dev->tsc_cell != -1)
+		tscadc_idle_config(tscadc_dev);
 	am335x_tsc_se_update(tscadc_dev);
 	restore = tscadc_readl(tscadc_dev, REG_CTRL);
 	tscadc_writel(tscadc_dev, REG_CTRL,
-- 
1.7.9.5

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